Hierarchical channel mordenite, methods of making the same, and use in naphthylalkylation

Abstract

The present application belongs to the technical field of molecular sieve synthesis and catalytic material, and particularly relates to a hierarchical pore mordenite, a preparation method thereof and application of the hierarchical pore mordenite in naphthalene alkylation. 4+ Substitute Na + Afterwards, the sodium type hierarchical pore mordenite is calcined to form active Si-OH-Al to obtain the hierarchical pore mordenite. The obtained hierarchical pore mordenite breaks the mass transfer limitation of one-dimensional micropore, inhibits the carbon deposition deactivation path, and realizes directional regulation of the acid site distribution and intensity, so that the industrial requirements of high activity, high 2,6-diisopropyl naphthalene selectivity and long cycle stability in naphthalene alkylation reaction are achieved, and the technical defects of the conventional mordenite catalyst in naphthalene alkylation reaction in the prior art are overcome.

Description

Technical Field

[0001] This invention belongs to the field of molecular sieve synthesis and catalytic materials technology, specifically involving hierarchical porous mordenite, its preparation method and its application in naphthalene alkylation. This hierarchical porous mordenite is used in the alkylation reaction of unsaturated aromatic hydrocarbons, especially in the reaction of naphthalene with alkylating reagents to prepare the target alkylated product. Background Technology

[0002] Since the pioneering research by Mobil researchers in the 1960s, the selective alkylation of benzene with alkylbenzenes on various zeolites has become a mature technological system, widely supporting the development of the fine chemical industry. However, as high-end polymer materials upgrade towards lightweighting and functionalization, the shortcomings in the research of selective alkylation of bicyclic aromatic hydrocarbons such as naphthalene and biphenyl are becoming increasingly prominent, and related technologies remain relatively weak.

[0003] Naphthalene and its derivatives are widely found in coal tar and petroleum refining byproducts, making them highly valuable industrial raw materials. Currently, the demand for polyethylene naphthalate (PEG) or liquid crystal polymer materials in new display and new energy fields is surging. The domestic supply of its core monomer, 2,6-dialkylnaphthalene, has become an industry bottleneck. This monomer requires extremely high β-selective alkylation efficiency at the naphthalene position, directly restricting the independent production of high-end polyester materials. Therefore, research on the β-selective alkylation reaction of naphthalene has become a key direction for meeting the needs of industrial upgrading and overcoming raw material constraints.

[0004] The alkylation of naphthalene with alkenes and haloalkanes is a typical Friedel-Crafts reaction. Traditional processes often use homogeneous acid catalysts such as H₂SO₄, HF, and AlCl₃. While these catalysts exhibit high activity at 50°C to 100°C, they suffer from problems such as equipment corrosion, difficult separation, and complex waste treatment. Furthermore, AlCl₃ poses environmental risks, contradicting current industrial greening requirements. To address the limitations of homogeneous catalysis, the industry has turned its attention to heterogeneous acid catalysts, with zeolites and heteropolyacids being key research areas. Heteropolyacids exhibit high activity under relatively mild conditions, while zeolites, due to their uniform pore structure, strong acidity, and shape-selective catalysis capabilities, have become crucial catalysts in the chemical and refining industries. They can recognize molecular size and shape through pore space interaction, meeting the selectivity requirements of fine chemicals. Currently, mordenite, Hβ, ZSM-5, and MCM series zeolites with special pore structures have been used in naphthalene alkylation research in fixed-bed or batch reactors.

[0005] To address the challenges of homogeneous catalysis with acid corrosion, heterogeneous catalysis with high temperature and pressure, and insufficient selectivity in naphthalene alkylation reactions, zeolite catalysts, especially mordenite, have emerged as a core candidate to replace traditional liquid acids due to their unique pore topology and precisely tunable acidity. In the crystal structure of mordenite, the pore size of the twelve-membered ring main channel is approximately 0.65 nm × 0.70 nm, while the kinetic diameter of the naphthalene molecule is approximately 0.69 nm. The size of the twelve-membered ring main channel is highly compatible with the naphthalene molecule. This "spatial matching" can directly regulate the product formation pathway through shape-selective confinement. Theoretically, its channels can preferentially accommodate 2,6-diisopropylnaphthalene with relatively low steric hindrance, while inhibiting the formation of more sterically hindered isomers, such as 2,7-diisopropylnaphthalene, providing a structural basis for the targeted synthesis of the target product. Currently, conventional mordenite zeolite catalysts in the industry are prepared by using tetraethylammonium hydroxide as a template agent, which is obtained by hydrothermal crystallization of aluminosilicate gel containing the template agent and then removing the template agent. However, conventional mordenite zeolite catalysts in the industry still face three major technical bottlenecks that are difficult to overcome in practical large-scale applications, which seriously restrict their industrialization process:

[0006] 1. Mass transfer limitation is a prominent issue, resulting in low catalytic efficiency and selectivity. Conventional mordenite catalysts are typical one-dimensional microporous materials, and their single-channel structure significantly hinders the diffusion of naphthalene and product molecules. For reactants, the kinetic diameter of naphthalene molecules is about 0.69 nm. Although they can enter the 0.65 nm × 0.70 nm main channel, the narrow space leads to an extremely low diffusion rate. A large number of naphthalene molecules cannot quickly reach the acidic active sites within the channel, directly causing the catalyst to have "low active site utilization" and a significant decrease in apparent catalytic activity. For the product, the generated diisopropylnaphthalene molecule has a dynamic diameter >0.8 nm, which is much larger than the pore size. It cannot be desorbed from the pores quickly and can only remain in the pores for a long time. This retention will not only trigger deep alkylation and isomerization side reactions, but deep alkylation will generate polyisopropylnaphthalene byproducts and isomerization will convert the target 2,6-diisopropylnaphthalene into 2,7-diisopropylnaphthalene isomers. It will also further squeeze the pore space, increase the mass transfer resistance, and ultimately form a vicious cycle of "poor mass transfer → more side reactions → decreased selectivity".

[0007] 2. Rapid deactivation due to carbon buildup leads to high industrial operating costs. Another key problem caused by mass transfer limitations is catalyst deactivation due to carbon buildup: naphthalene molecules, reaction intermediates, and byproducts retained in the pores are prone to condensation and dehydrogenation reactions induced by acidic sites, forming large-molecule polycyclic aromatic hydrocarbons, i.e., "carbon buildup." This carbon buildup damages catalyst performance in two ways: physically, carbon deposits adhere to the inner walls of the pores or block the pore openings, directly cutting off the contact channel between reactants and active sites; chemically, carbon buildup covers the acidic active sites within the pores, causing simultaneous decay of catalyst acidity and activity. Existing research data shows that the single-pass lifetime of conventional mordenite zeolite catalysts in naphthalene alkylation reactions is typically less than 100 hours, requiring frequent high-temperature carbonization regeneration. Regeneration temperatures often exceed 500℃. Frequent regeneration operations not only interrupt continuous production processes but also increase energy consumption and equipment wear, significantly increasing the complexity and economic cost of industrial operation.

[0008] 3. Insufficient precision in acid site control leads to product selectivity that fails to meet industrial requirements. The distribution and intensity of acid sites in conventional mordenite catalysts have not yet achieved a precise match with the requirements of naphthalene alkylation reactions. Specifically, a large number of strong acid sites unrestricted by the pores exist at the non-shape-selective strong acid centers on the outer surface and pore inlets of conventional mordenite catalysts. These sites cannot selectively sieve molecules through spatial geometry and are prone to catalyzing non-target reactions, such as the random alkylation of naphthalene, resulting in the formation of large amounts of 2,7-diisopropylnaphthalene and other isomers. Furthermore, the excessively high acid strength of some strong acid sites within the pores not only accelerates the deep alkylation of naphthalene but also promotes the formation of carbon deposit precursors, further exacerbating carbon deposition and deactivation. As a result, the molar ratio of 2,6-diisopropylnaphthalene to 2,7-diisopropylnaphthalene in conventional mordenite catalytic products is typically less than 3, while the ideal ratio for preparing high-performance polymers in industry is much higher. For example, in the preparation of polyethylene naphthalate, the current selectivity level is far from meeting the needs of industrial production. Summary of the Invention

[0009] This invention addresses key issues existing with conventional mordenite catalysts in naphthalene alkylation reactions by proposing a hierarchical porous mordenite zeolite, its preparation method, and its application in naphthalene alkylation. Compared to existing technologies, this invention uses an ionic liquid as a template agent to replace the tetraethylammonium hydroxide template agent in existing technologies. The hierarchical porous mordenite zeolite is then prepared via ion exchange and sintering. The resulting hierarchical porous mordenite zeolite overcomes the technical defects of conventional mordenite catalysts in naphthalene alkylation reactions. In the naphthalene alkylation reaction, the selectivity of 2,6-diisopropylnaphthalene using the hierarchical porous mordenite zeolite of this invention is higher than 47%, and the naphthalene conversion rate decreases by less than 10% after 200 hours of continuous operation.

[0010] To address the aforementioned technical problems, the present invention adopts the following technical solution: This invention solves two core problems—low mass transfer efficiency and difficulty in acid control—by precisely controlling the pore structure and acidic site distribution of hierarchical mordenite. This enables the high-selectivity and high-yield production of 2,6-diisopropylnaphthalene in naphthalene alkylation reactions, as well as the long-term stable operation of hierarchical mordenite, providing key technical support for industrial applications.

[0011] This invention protects multi-level porous mordenite, which is based on... , , , One of the methods involves using a template agent. This is achieved by hydrothermally crystallizing an aluminosilicate gel containing the template agent, removing the template agent, and then obtaining sodium-type hierarchical porous mordenite. The sodium-type hierarchical porous mordenite is then subjected to ion exchange using NH4+. 4+ Replace Na + Subsequently, sintering is performed to form active Si-OH-Al linked hydroxyl groups; its core innovation lies in the use of specific ionic liquids as template directing agents and mesoporous generation templates in the hydrothermal synthesis system.

[0012] Preferably, the total specific surface area of ​​the hierarchical porous mordenite is 350 m². 2 / g~450m 2 / g.

[0013] Preferably, the total pore volume of the hierarchical porous mordenite is 0.25 cm³. 3 / g~0.35cm 3 / g, of which the mesoporous pore volume is 0.05cm³. 3 / g~0.1cm 3 / g.

[0014] Preferably, in the hierarchical porous mordenite, the molar ratio of Brønsted acid sites to Lewis acid sites is 5~10:1.

[0015] This invention also protects a method for preparing multi-level porous mordenite zeolite, comprising the following steps: S1. Mix the silicon source, aluminum source, alkali source and deionized water, and stir at room temperature to form a uniform initial gel.

[0016] S2. Add a predetermined amount of ionic liquid to the initial gel and continue stirring to obtain the final gel for crystallization, namely, a silicate gel containing a template agent.

[0017] Among them, ionic liquids are selected from , , , One of them.

[0018] S3. The aluminosilicate gel containing the template agent is transferred to a hydrothermal reactor for static hydrothermal crystallization. After hydrothermal crystallization, the gel is cooled, filtered, washed, and dried to obtain zeolite powder.

[0019] S4. The zeolite powder is calcined at high temperature to completely remove the template agent, resulting in sodium-type multi-level porous mordenite.

[0020] S5. Sodium-type hierarchical mordenite zeolite is ion-exchanged with an ammonium salt solution. Without ion exchange, the sodium-type hierarchical mordenite zeolite remains sodium-type or contains cations, lacking the Brønsted acid sites required for the catalytic isopropylation of naphthalene. Therefore, without ion exchange, it has almost no catalytic activity. The principle of ion exchange is that the AlO tetrahedra in the sodium-type hierarchical mordenite framework are negatively charged and require cation balance. In the synthesis process, Na+ is usually used. + To achieve cation equilibrium, sodium-type hierarchical porous mordenite is immersed in an ammonium salt solution. Utilizing the concentration gradient and the difference in ion affinity, NH... 4+ Diffusion enters the pores and replaces Na through electrostatic interactions. + After washing, drying, and final sintering, the target product—hierarchical porous mordenite—is obtained. Final sintering causes the ammonium ions in the ion-exchanged ammonium zeolite to decompose at high temperature, producing ammonia gas which escapes, leaving only protons (H₂O). + By combining with skeletal oxygen atoms, active Si-OH-Al linked hydroxyl groups are formed, resulting in catalytically active hydrogen-type hierarchical porous mordenite.

[0021] Preferably, in the aluminosilicate gel containing the template agent, the molar ratio of each component is SiO2:Al2O3=(15~50):1; template agent:SiO2=(0.05~0.2):1; H2O:SiO2=(20~50):1. Further, SiO2:Al2O3=(20~30):1.

[0022] Preferably, the hydrothermal crystallization conditions are: hydrothermal crystallization at 150℃~200℃ for 48h~120h.

[0023] Preferably, the ion exchange method is as follows: sodium-type hierarchical porous mordenite is placed in an ammonium salt solution and stirred at 70℃~95℃ for 4h~12h, and repeated at least 3 times.

[0024] Preferably, the calcination conditions are: calcination at 500℃~600℃ for 4h~8h.

[0025] Preferably, the sintering conditions are: calcination at 400℃~550℃ for 2h~12h.

[0026] This invention further discloses the application of hierarchical porous mordenite as a catalyst in naphthalene alkylation reaction, and the application method is as follows: Using naphthalene and propylene as raw materials, and hierarchical mordenite as catalyst, the reaction was carried out at a temperature of 200℃~325℃, a reaction pressure of 1.0MPa~5.0MPa, a molar ratio of naphthalene to propylene of 1:2~6, and a mass hourly space velocity of 1h⁻¹. −1 ~5h −1 Under certain conditions, naphthalene alkylation reaction is carried out; wherein, the mass hourly space velocity is the flow rate ratio of the total mass of naphthalene and propylene to the mass of the catalyst, mordenite.

[0027] The core innovation of this invention lies in constructing a combination of physicochemical properties that combine specific pore topology with precise acidity control. This synergistic effect endows hierarchical mordenite zeolite with catalytic performance far exceeding that of conventional mordenite catalysts. Hierarchical mordenite zeolite possesses the following core physicochemical characteristics:

[0028] 1. Unique microporous-mesoporous hierarchical pore structure: Nitrogen adsorption-desorption isotherm testing confirmed that the isotherm of the hierarchical mordenite exhibits typical Type I and Type IV composite characteristics, accompanied by an H4 type hysteresis loop. This is a direct structural characterization of the coexistence of micropores and mesopores. Its key pore structure parameters are: total specific surface area of ​​390 m² / g. 2 / g~460m 2 / g, of which the external specific surface area contributed by mesopores accounts for as high as 30%~50%, which is 3 to 5 times higher than that of conventional mordenite zeolite catalysts, which are usually less than 10%; the total pore volume reaches 0.25cm³. 3 / g~0.35cm 3 / g, of which mesoporous pore volume accounts for 40%~57%, and the mesoporous pore volume is 0.10cm³. 3 / g~0.20cm 3 / g. This hierarchical pore structure constructs a dual-functional channel system of "rapid transport and precise shape selection". Mesopores provide efficient transport paths for reactant / product molecules, while micropores maintain the inherent shape-selective catalytic ability of mordenite.

[0029] 2. Precisely Controlled Distribution and Intensity of Acidic Sites: Characterization using ammonia-programmed temperature desorption confirmed that the acidity of the hierarchical mordenite zeolite was precisely controlled. Under desorption conditions of 150℃, the molar ratio of the integral area of ​​Brønsted acid sites to Lewis acid sites remained stably maintained in a high range of 5-10, ensuring the number of main active sites required for the naphthalene alkylation reaction. In addition, the ammonia-programmed temperature desorption spectrum showed that the peak temperature of the high-temperature desorption peak corresponding to the strong acid sites was significantly lower than that of conventional mordenite zeolite catalysts, indicating that the strength of the strong acid centers was moderately weakened, effectively suppressing the occurrence of non-target side reactions.

[0030] 3. This invention also discloses the application of the above-mentioned hierarchical porous mordenite zeolite in the alkylation of naphthalene to prepare 2,6-diisopropylnaphthalene. Compared with conventional mordenite catalysts in the prior art, its core advantages and beneficial effects are reflected in the following four aspects: (1) Breakthrough improvement in shape selectivity: The microporous-mesoporous hierarchical structure of the multi-level porous mordenite fundamentally alleviates the mass transfer limitation. The kinetic diameter of naphthalene molecules is 0.69 nm, and naphthalene molecules can rapidly diffuse to the active sites in the micropores through the mesoporous channels. The kinetic diameter of the product 2,6-diisopropylnaphthalene is >0.8 nm, and it can be rapidly desorbed through the mesopores, shortening the residence time of molecules in the channels and inhibiting the deep alkylation and isomerization side reactions from the source. At the same time, the molar ratio of the integral area of ​​high Brønsted acid sites to Lewis acid sites of 5~10 and the moderately weakened strong acid centers further inhibit the non-shape-selective alkylation reaction on the outer surface. Under the dual effect, the selectivity of 2,6-diisopropylnaphthalene stably reaches more than 75%, and the highest reaches 82%. The molar ratio of 2,6-diisopropylnaphthalene / 2,7-diisopropylnaphthalene is increased from <3 in conventional catalysts to 5~7, which greatly reduces the energy consumption and cost of subsequent separation and purification, and breaks through the industrial-grade selectivity bottleneck.

[0031] (2) Significantly extended anti-coking stability and catalytic life: The highly efficient mesoporous mass transfer channels prevent the accumulation of reactants, intermediates, and byproducts within the channels, inhibiting the formation of polycyclic aromatic hydrocarbon (PAH) coking precursors from the source. Fixed-bed continuous operation tests show that the single-pass life of multi-level porous mordenite zeolite can reach 200-280 hours, which is 3-5 times that of conventional mordenite zeolite catalysts, while conventional mordenite zeolite catalysts have a life of <100 hours. The ultra-long life significantly reduces the frequency of high-temperature carbonization regeneration, ensuring the stability of the continuous production process while reducing energy consumption and equipment wear during regeneration, thus significantly reducing industrial operating costs.

[0032] (3) Catalytic activity and target product yield are improved simultaneously: The mesoporous channels break through the mass transfer bottleneck, increasing the utilization rate of acidic active sites in the micropores by more than 40%, and significantly enhancing the apparent catalytic activity. Under optimized reaction conditions, the naphthalene conversion rate is stably maintained at more than 90%, combined with a high selectivity of more than 40%, and the single-pass yield of 2,6-diisopropylnaphthalene exceeds 40%, which is higher than <40% of the existing technology, achieving a synergistic improvement in activity and selectivity.

[0033] (4) The preparation process is both innovative and controllable: This invention innovatively uses ionic liquids as template agents and employs a one-step synthesis process, which has the advantages of simple process and high repeatability, with batch-to-batch performance deviations of <5%. By controlling the type of anionic ligands in the template agent, precise control of mesopore size and pore volume can be achieved, with mesopore size ranging from 2nm to 5nm and pore volume of 0.10cm. 3 / g~0.20cm3 / g, thereby enabling the directional design of pore structure and catalytic performance. This strategy provides a new paradigm for the rational design of shape-selective catalysts and has the potential for large-scale industrial production. Attached Figure Description

[0034] Figure 1 The X-ray diffraction patterns are those of the multi-level porous mordenite zeolite of Examples 1 to 12 of the present invention and the conventional mordenite catalysts of Comparative Examples 1 to 3, used to characterize the crystal structure and phase purity of the catalysts.

[0035] Figure 2 The nitrogen adsorption-desorption isotherms and pore size distribution diagrams of the multi-level porous mordenite zeolite of Examples 1 to 12 and the conventional mordenite catalysts of Comparative Examples 1 to 3 are used to analyze the pore type, specific surface area and pore size distribution characteristics of the catalysts.

[0036] Figure 3 These are scanning electron microscope images of the multi-level porous mordenite zeolite of Examples 1 to 12 of the present invention and the conventional mordenite catalysts of Comparative Examples 1 to 3, used to observe the microstructure and particle size distribution of the catalysts.

[0037] Figure 4 The graphs show the ammonia temperature-programmed desorption curves of multi-level porous mordenite zeolite in Examples 1, 6, 8 and 10 of this invention.

[0038] Figure 5 The ammonia temperature-programmed desorption curves of the multi-level porous mordenite zeolite of Examples 1 to 12 of the present invention and the conventional mordenite zeolite catalysts of Comparative Examples 1 to 3 are used to analyze the intensity distribution characteristics of the acidic sites of the catalysts.

[0039] Figure 6 This is a graph showing the catalytic performance test of the catalyst in the alkylation reaction of naphthalene and propylene to synthesize diisopropylnaphthalene. Detailed Implementation

[0040] The present invention will be specifically described below through embodiments. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above content.

[0041] Considering the technical defects of existing conventional mordenite zeolite catalysts, specifically, existing conventional mordenite zeolite catalysts mainly face the following three major bottlenecks: First, due to its microporous structure, the mass transfer resistance between reactants and products is large, resulting in low catalytic activity, and the yield of the target product 2,6-diisopropylnaphthalene is generally less than 40%; Second, the combined effect of mass transfer limitation and insufficient acid regulation causes easy carbon deposition on the catalyst surface, rapid deactivation, and a single-pass service life of usually less than 100 hours; In addition, due to the lack of sufficient shape selectivity in the reaction pathway, side reactions are more prominent, resulting in unsatisfactory selectivity of the target product, and the molar ratio of 2,6-diisopropylnaphthalene to 2,7-diisopropylnaphthalene is often less than 3. This invention develops a mordenite-based catalyst with both efficient mass transfer structure and precise acidity control, namely a hierarchical mordenite. It can overcome the mass transfer limitations of one-dimensional micropores, inhibit carbon deposition and deactivation pathways, and achieve directional control of the distribution and intensity of acidic sites. Thus, it can simultaneously meet the industrial requirements of high activity, high selectivity for 2,6-diisopropylnaphthalene, and long cycle stability in naphthalene alkylation reactions.

[0042] The names and structural formulas of the ionic liquid template agents used in the examples are shown below: , , , , It is 1-butyl-3-methylpyridine-1-onium tetrafluoroborate. It is 1-butyl-3-methylimidazolium bromide. It is 1-butyl-3-methylimidazolium trifluoromethanesulfonate. It is 1-ethyl-2,3-dimethylimidazolium chloride.

[0043] The technical solution of the present invention will be studied below using examples and comparative examples. The specific research methods and results are shown below: Example 1 A method for preparing hierarchical porous mordenite zeolite using 1-butyl-3-methylpyridine-1-onium tetrafluoroborate template agent, wherein the hierarchical porous mordenite zeolite is [C4mpy]BF4-MOR (Si / Al10), includes the following steps: S1. Preparation of aluminosilicate gel containing a template agent: Weigh 4.10 g of sodium aluminate, 2 g of sodium hydroxide, and 77 g of deionized water, and mix and stir until the solution is clear. Then, under vigorous stirring, add 50 g of silica sol (30 wt% SiO2 in the silica sol) dropwise to the above solution, and continue stirring for 10 min. Then add 4.47 g of 1-butyl-3-methylpyridin-1-onium tetrafluoroborate template agent, and continue stirring for 4 h to form a uniform, white gel. The molar composition of the gel is: 1SiO2:0.2Na2O:0.1Al2O3:23H2O:0.1SDA, where SDA is the abbreviation for template agent.

[0044] S2. Hydrothermal crystallization: The gel was transferred to a 200 mL hydrothermal reactor with a polytetrafluoroethylene liner and subjected to static hydrothermal reaction at 170 °C for 120 h to obtain the crystallized product.

[0045] S3. Post-processing: The crystallized product is cooled, filtered, washed with deionized water until neutral, and dried at 110°C to obtain zeolite powder.

[0046] S4. Template Agent Removal and Ion Exchange: The zeolite powder was placed in a muffle furnace and calcined at 550℃ for 6 hours to remove the template agent. Then, ion exchange was performed three times at 85℃ in a 1 mol / L NH4Cl solution, each time for 6 hours. The exchanged sample was dried and then calcined again in a muffle furnace at 550℃ for 4 hours to obtain the final hierarchical porous mordenite [C4mpy]BF4-MOR (Si / Al10).

[0047] Catalytic performance evaluation: The alkylation reaction of naphthalene and propylene was evaluated according to the above analytical methods.

[0048] Characterization and performance results: The physicochemical properties and performance data of the catalyst are summarized in Tables 1 and 2.

[0049] Example 2 A method for preparing hierarchical porous mordenite zeolite using 1-butyl-3-methylpyridine-1-onium tetrafluoroborate template agent, wherein the hierarchical porous mordenite zeolite is [C4mpy]BF4-MOR (Si / Al2O), includes the following steps: S1. Preparation of aluminosilicate gel containing template agent: Weigh 2.04 g of sodium aluminate, 2.96 g of sodium hydroxide, and 77 g of deionized water, and mix and stir until the solution is clear. Then, under vigorous stirring, add 50 g of silica sol (30 wt% SiO2 in the silica sol) dropwise to the above solution, and continue stirring for 10 min. Then add 4.47 g of 1-butyl-3-methylpyridin-1-onium tetrafluoroborate template agent, and continue stirring for 4 h to form a uniform, white gel. The molar composition of the gel is: 1SiO2:0.2Na2O:0.05Al2O3:23H2O:0.1SDA.

[0050] S2. Hydrothermal crystallization: The above gel was transferred to a 200 mL hydrothermal reactor with a polytetrafluoroethylene liner and subjected to static hydrothermal reaction at 170 °C for 120 h to obtain the crystallized product.

[0051] S3. Post-processing: The crystallized product is cooled, filtered, washed with deionized water until neutral, and dried at 110°C to obtain zeolite powder.

[0052] S4. Template Agent Removal and Ion Exchange: The zeolite powder was placed in a muffle furnace and calcined at 550℃ for 6 hours to remove the template agent. Then, ion exchange was performed three times at 85℃ in a 1 mol / L NH4Cl solution, each time for 6 hours. After drying, the exchanged sample was calcined again in a muffle furnace at 550℃ for 4 hours to obtain the final hierarchical porous mordenite [C4mpy]BF4-MOR (Si / Al2O).

[0053] Catalytic performance evaluation: The alkylation reaction of naphthalene and propylene was evaluated according to the above analytical methods.

[0054] Characterization and performance results: The physicochemical properties and performance data of the catalyst are summarized in Tables 1 and 2.

[0055] Example 3 A method for preparing hierarchical porous mordenite zeolite using 1-butyl-3-methylpyridine-1-onium tetrafluoroborate template agent, wherein the hierarchical porous mordenite zeolite is [C4mpy]BF4-MOR (Si / Al30), includes the following steps: S1. Preparation of aluminosilicate gel containing template agent: Weigh 1.36 g of sodium aluminate, 3.3 g of sodium hydroxide, and 77 g of deionized water, and mix and stir until the solution is clear. Then, under vigorous stirring, add 50 g of silica sol (SiO2 content 30 wt%) to the above solution and continue stirring for 10 min. Then add 4.47 g of 1-butyl-3-methylpyridine-1-onium tetrafluoroborate template agent and continue stirring for 4 h to form a uniform, white gel. The molar composition of the gel is: 1SiO2:0.2Na2O:0.033Al2O3:23H2O:0.1SDA.

[0056] S2. Hydrothermal crystallization: The above gel was transferred to a 200 mL hydrothermal reactor with a polytetrafluoroethylene liner and subjected to static hydrothermal reaction at 170 °C for 120 h to obtain the crystallized product.

[0057] S3. Post-processing: The crystallized product is cooled, filtered, washed with deionized water until neutral, and dried at 110°C to obtain zeolite powder.

[0058] S4. Template Agent Removal and Ion Exchange: The zeolite powder was placed in a muffle furnace and calcined at 550℃ for 6 hours to remove the template agent. Then, ion exchange was performed three times at 85℃ in a 1 mol / L NH4Cl solution, each time for 6 hours. After drying, the exchanged sample was calcined again in a muffle furnace at 550℃ for 4 hours to obtain the final hierarchical porous mordenite [C4mpy]BF4-MOR (Si / Al30).

[0059] Catalytic performance evaluation: The alkylation reaction of naphthalene and propylene was evaluated according to the above analytical methods.

[0060] Characterization and performance results: The physicochemical properties and performance data of the catalyst are summarized in Tables 1 and 2.

[0061] Example 4 A method for preparing hierarchical porous mordenite zeolite using 1-butyl-3-methylimidazolium bromide template agent, wherein the hierarchical porous mordenite zeolite is [C4mim]Br-MOR (Si / Al10), includes the following steps: S1. Preparation of aluminosilicate gel containing template agent: Weigh 4.10 g of sodium aluminate, 2 g of sodium hydroxide, and 77 g of deionized water, and mix and stir until the solution is clear. Then, under vigorous stirring, add 50 g of silica sol (30 wt% SiO2 in the silica sol) dropwise to the above solution, and continue stirring for 10 min. Then add 4.47 g of 1-butyl-3-methylimidazolium bromide template agent, and continue stirring for 4 h to form a uniform, white gel. The molar composition of the gel is: 1 SiO2:0.2 Na2O:0.1 Al2O3:23 H2O:0.1 SDA.

[0062] S2. Hydrothermal crystallization: The above gel was transferred to a 200 mL hydrothermal reactor with a polytetrafluoroethylene liner and subjected to static hydrothermal reaction at 170 °C for 120 h to obtain the crystallized product.

[0063] S3. Post-processing: The crystallized product is cooled, filtered, washed with deionized water until neutral, and dried at 110°C to obtain zeolite powder.

[0064] S4. Template Agent Removal and Ion Exchange: The zeolite powder was placed in a muffle furnace and calcined at 550℃ for 6 hours to remove the template agent. Then, ion exchange was performed three times at 85℃ in a 1 mol / L NH4Cl solution, each time for 6 hours. After drying, the exchanged sample was calcined again in a muffle furnace at 550℃ for 4 hours to obtain the final hierarchical porous mordenite [C4mim]Br-MOR (Si / Al10).

[0065] Catalytic performance evaluation: The alkylation reaction of naphthalene and propylene was evaluated according to the above analytical methods.

[0066] Characterization and performance results: The physicochemical properties and performance data of the catalyst are summarized in Tables 1 and 2.

[0067] Example 5 A method for preparing hierarchical porous mordenite zeolite using 1-butyl-3-methylimidazolium bromide template agent, wherein the hierarchical porous mordenite zeolite is [C4mim]Br-MOR (Si / Al2O), includes the following steps: S1. Preparation of aluminosilicate gel containing template agent: Weigh 2.04 g of sodium aluminate, 2.96 g of sodium hydroxide, and 77 g of deionized water, and mix and stir until the solution is clear. Then, under vigorous stirring, add 50 g of silica sol (30 wt% SiO2 in the silica sol) dropwise to the above solution, and continue stirring for 10 min. Then add 4.47 g of 1-butyl-3-methylimidazolium bromide template agent, and continue stirring for 4 h to form a uniform, white gel. The molar composition of the gel is: 1 SiO2:0.2 Na2O:0.05 Al2O3:23 H2O:0.1 SDA.

[0068] S2. Hydrothermal crystallization: The above gel was transferred to a 200 mL hydrothermal reactor with a polytetrafluoroethylene liner and subjected to static hydrothermal reaction at 170 °C for 120 h to obtain the crystallized product.

[0069] S3. Post-processing: The crystallized product is cooled, filtered, washed with deionized water until neutral, and dried at 110°C to obtain zeolite powder.

[0070] S4. Template Agent Removal and Ion Exchange: The zeolite powder was placed in a muffle furnace and calcined at 550℃ for 6 hours to remove the template agent. Then, ion exchange was performed three times at 85℃ in a 1 mol / L NH4Cl solution, each time for 6 hours. After drying, the exchanged sample was calcined again in a muffle furnace at 550℃ for 4 hours to obtain the final hierarchical porous mordenite [C4mim]Br-MOR (Si / Al2O).

[0071] Catalytic performance evaluation: The alkylation reaction of naphthalene and propylene was evaluated according to the above analytical methods.

[0072] Characterization and performance results: The physicochemical properties and performance data of the catalyst are summarized in Tables 1 and 2.

[0073] Example 6 A method for preparing hierarchical porous mordenite zeolite using 1-butyl-3-methylimidazolium bromide template agent, wherein the hierarchical porous mordenite zeolite is [C4mim]Br-MOR (Si / Al30), includes the following steps: S1. Preparation of aluminosilicate gel containing template agent: Weigh 1.36 g of sodium aluminate, 3.3 g of sodium hydroxide, and 77 g of deionized water, and mix and stir until the solution is clear. Then, under vigorous stirring, add 50 g of silica sol (30 wt% SiO2 in the silica sol) dropwise to the above solution, and continue stirring for 10 min. Then add 4.47 g of 1-butyl-3-methylimidazolium bromide template agent, and continue stirring for 4 h to form a uniform, white gel. The molar composition of the gel is: 1 SiO2:0.2 Na2O:0.033 Al2O3:23 H2O:0.1 SDA.

[0074] S2. Hydrothermal crystallization: The above gel was transferred to a 200 mL hydrothermal reactor with a polytetrafluoroethylene liner and subjected to static hydrothermal reaction at 170 °C for 120 h to obtain the crystallized product.

[0075] S3. Post-processing: The crystallized product is cooled, filtered, washed with deionized water until neutral, and dried at 110°C to obtain zeolite powder.

[0076] S4. Template Agent Removal and Ion Exchange: The zeolite powder was placed in a muffle furnace and calcined at 550℃ for 6 hours to remove the template agent. Then, ion exchange was performed three times at 85℃ in a 1 mol / L NH4Cl solution, each time for 6 hours. After drying, the exchanged sample was calcined again in a muffle furnace at 550℃ for 4 hours to obtain the final hierarchical porous mordenite [C4mim]Br-MOR (Si / Al30).

[0077] Catalytic performance evaluation: The alkylation reaction of naphthalene and propylene was evaluated according to the above analytical methods.

[0078] Characterization and performance results: The physicochemical properties and performance data of the catalyst are summarized in Tables 1 and 2.

[0079] Example 7 A method for preparing hierarchical porous mordenite zeolite using 1-butyl-3-methylimidazolium trifluoromethanesulfonate template agent, wherein the hierarchical porous mordenite zeolite is [C4mim]OTf-MOR(Si / Al10), includes the following steps: S1. Preparation of aluminosilicate gel containing template agent: Weigh 4.10 g of sodium aluminate, 2 g of sodium hydroxide, and 77 g of deionized water, and mix and stir until the solution is clear. Then, under vigorous stirring, add 50 g of silica sol (SiO2 content 30 wt%) to the above solution and continue stirring for 10 min. Then add 4.47 g of 1-butyl-3-methylimidazolium trifluoromethanesulfonate template agent and continue stirring for 4 h to form a uniform, white gel. The molar composition of the gel is: 1 SiO2:0.2 Na2O:0.1 Al2O3:23 H2O:0.1 SDA.

[0080] S2. Hydrothermal crystallization: The above gel was transferred to a 200 mL hydrothermal reactor with a polytetrafluoroethylene liner and subjected to static hydrothermal reaction at 170 °C for 120 h to obtain the crystallized product.

[0081] S3. Post-processing: The crystallized product is cooled, filtered, washed with deionized water until neutral, and dried at 110°C to obtain zeolite powder.

[0082] S4. Template Agent Removal and Ion Exchange: The zeolite powder was placed in a muffle furnace and calcined at 550℃ for 6 hours to remove the template agent. Then, ion exchange was performed three times at 85℃ in a 1 mol / L NH4Cl solution, each time for 6 hours. After drying, the exchanged sample was calcined again in a muffle furnace at 550℃ for 4 hours to obtain the final hierarchical porous mordenite [C4mim]OTF-MOR (Si / Al10).

[0083] Catalytic performance evaluation: The alkylation reaction of naphthalene and propylene was evaluated according to the above analytical methods.

[0084] Characterization and performance results: The physicochemical properties and performance data of the catalyst are summarized in Tables 1 and 2.

[0085] Example 8 A method for preparing hierarchical porous mordenite zeolite using 1-butyl-3-methylimidazolium trifluoromethanesulfonate template agent, wherein the hierarchical porous mordenite zeolite is [C4mim]OTF-MOR(Si / Al2O), includes the following steps: S1. Preparation of aluminosilicate gel containing template agent: Weigh 2.04 g of sodium aluminate, 2.96 g of sodium hydroxide, and 77 g of deionized water, and mix and stir until the solution is clear. Then, under vigorous stirring, add 50 g of silica sol (SiO2 content 30 wt%) to the above solution and continue stirring for 10 min. Then add 4.47 g of 1-butyl-3-methylimidazolium trifluoromethanesulfonate template agent and continue stirring for 4 h to form a uniform, white gel. The molar composition of the gel is: 1SiO2:0.2Na2O:0.05Al2O3:23H2O:0.1SDA.

[0086] S2. Hydrothermal crystallization: The above gel was transferred to a 200 mL hydrothermal reactor with a polytetrafluoroethylene liner and subjected to static hydrothermal reaction at 170 °C for 120 h to obtain the crystallized product.

[0087] S3. Post-processing: The crystallized product is cooled, filtered, washed with deionized water until neutral, and dried at 110°C to obtain zeolite powder.

[0088] S4. Template Agent Removal and Ion Exchange: The zeolite powder was placed in a muffle furnace and calcined at 550℃ for 6 hours to remove the template agent. Then, ion exchange was performed three times at 85℃ in a 1 mol / L NH4Cl solution, each time for 6 hours. After drying, the exchanged sample was calcined again in a muffle furnace at 550℃ for 4 hours to obtain the final hierarchical porous mordenite [C4mim]OTF-MOR (Si / Al2O).

[0089] Catalytic performance evaluation: The alkylation reaction of naphthalene and propylene was evaluated according to the above analytical methods.

[0090] Characterization and performance results: The physicochemical properties and performance data of the catalyst are summarized in Tables 1 and 2.

[0091] Example 9 A method for preparing hierarchical porous mordenite zeolite using 1-butyl-3-methylimidazolium trifluoromethanesulfonate template agent, wherein the hierarchical porous mordenite zeolite is [C4mim]OTF-MOR (Si / Al30), includes the following steps: S1. Preparation of aluminosilicate gel containing template agent: Weigh 1.36 g of sodium aluminate, 3.3 g of sodium hydroxide, and 77 g of deionized water, and mix and stir until the solution is clear. Then, under vigorous stirring, add 50 g of silica sol (30 wt% SiO2 in the silica sol) dropwise to the above solution, and continue stirring for 10 min. Then add 4.47 g of 1-butyl-3-methylimidazolium trifluoromethanesulfonate template agent, and continue stirring for 4 h to form a uniform, white gel. The molar composition of the gel is: 1SiO2:0.2Na2O:0.033Al2O3:23H2O:0.1SDA.

[0092] S2. Hydrothermal crystallization: The above gel was transferred to a 200 mL hydrothermal reactor with a polytetrafluoroethylene liner and subjected to static hydrothermal reaction at 170 °C for 120 h to obtain the crystallized product.

[0093] S3. Post-processing: The crystallized product is cooled, filtered, washed with deionized water until neutral, and dried at 110°C to obtain zeolite powder.

[0094] S4. Template Agent Removal and Ion Exchange: The zeolite powder was placed in a muffle furnace and calcined at 550℃ for 6 hours to remove the template agent. Then, ion exchange was performed three times at 85℃ in a 1 mol / L NH4Cl solution, each time for 6 hours. After drying, the exchanged sample was calcined again in a muffle furnace at 550℃ for 4 hours to obtain the final hierarchical porous mordenite [C4mim]OTF-MOR (Si / Al30).

[0095] Catalytic performance evaluation: The alkylation reaction of naphthalene and propylene was evaluated according to the above analytical methods.

[0096] Characterization and performance results: The physicochemical properties and performance data of the catalyst are summarized in Tables 1 and 2.

[0097] Example 10 A method for preparing hierarchical porous mordenite zeolite using 1-ethyl-2,3-dimethylimidazolium chloride template agent, wherein the hierarchical porous mordenite zeolite is [C2dmim]Cl-MOR (Si / Al10), includes the following steps: S1. Preparation of aluminosilicate gel containing a template agent: Weigh 4.10 g of sodium aluminate, 2 g of sodium hydroxide, and 77 g of deionized water, and mix and stir until the solution is clear. Then, under vigorous stirring, add 50 g of silica sol (30 wt% SiO2 in the silica sol) dropwise to the above solution, and continue stirring for 10 min. Then add 4.47 g of 1-ethyl-2,3-dimethylimidazolium chloride template agent, and continue stirring for 4 h to form a uniform, white gel. The molar composition of the gel is: 1 SiO2:0.2 Na2O:0.1 Al2O3:23 H2O:0.1 SDA.

[0098] S2. Hydrothermal crystallization: The above gel was transferred to a 200 mL hydrothermal reactor with a polytetrafluoroethylene liner and subjected to static hydrothermal reaction at 170 °C for 120 h to obtain the crystallized product.

[0099] S3. Post-processing: The crystallized product is cooled, filtered, washed with deionized water until neutral, and dried at 110°C to obtain zeolite powder.

[0100] S4. Template Agent Removal and Ion Exchange: The zeolite powder was placed in a muffle furnace and calcined at 550℃ for 6 hours to remove the template agent. Then, ion exchange was performed three times at 85℃ in a 1 mol / L NH4Cl solution, each time for 6 hours. After drying, the exchanged sample was calcined again in a muffle furnace at 550℃ for 4 hours to obtain the final hierarchical porous mordenite [C2dmim]Cl-MOR (Si / Al10).

[0101] Catalytic performance evaluation: The alkylation reaction of naphthalene and propylene was evaluated according to the above analytical methods.

[0102] Characterization and performance results: The physicochemical properties and performance data of the catalyst are summarized in Tables 1 and 2.

[0103] Example 11 A method for preparing hierarchical porous mordenite zeolite using 1-ethyl-2,3-dimethylimidazolium chloride template agent, wherein the hierarchical porous mordenite zeolite is [C2dmim]Cl-MOR (Si / Al2O), includes the following steps: S1. Preparation of aluminosilicate gel containing template agent: Weigh 2.04 g of sodium aluminate, 2.96 g of sodium hydroxide, and 77 g of deionized water, and mix and stir until the solution is clear. Then, under vigorous stirring, add 50 g of silica sol (30 wt% SiO2 in the silica sol) dropwise to the above solution, and continue stirring for 10 min. Then add 4.47 g of 1-ethyl-2,3-dimethylimidazolium chloride template agent, and continue stirring for 4 h to form a uniform, white gel. The molar composition of the gel is: 1 SiO2:0.2 Na2O:0.05 Al2O3:23 H2O:0.1 SDA.

[0104] S2. Hydrothermal crystallization: The above gel was transferred to a 200 mL hydrothermal reactor with a polytetrafluoroethylene liner and subjected to static hydrothermal reaction at 170 °C for 120 h to obtain the crystallized product.

[0105] S3. Post-processing: The crystallized product is cooled, filtered, washed with deionized water until neutral, and dried at 110°C to obtain zeolite powder.

[0106] S4. Template Agent Removal and Ion Exchange: The zeolite powder was placed in a muffle furnace and calcined at 550℃ for 6 hours to remove the template agent. Then, ion exchange was performed three times at 85℃ in a 1 mol / L NH4Cl solution, each time for 6 hours. After drying, the exchanged sample was calcined again in a muffle furnace at 550℃ for 4 hours to obtain the final hierarchical porous mordenite [C2dmim]Cl-MOR (Si / Al2O).

[0107] Catalytic performance evaluation: The alkylation reaction of naphthalene and propylene was evaluated according to the above analytical methods.

[0108] Characterization and performance results: The physicochemical properties and performance data of the catalyst are summarized in Tables 1 and 2.

[0109] Example 12 A method for preparing hierarchical porous mordenite zeolite using 1-ethyl-2,3-dimethylimidazolium chloride template agent, wherein the hierarchical porous mordenite zeolite is [C2dmim]Cl-MOR (Si / Al30), includes the following steps: S1. Preparation of aluminosilicate gel containing template agent: Weigh 1.36 g of sodium aluminate, 3.3 g of sodium hydroxide, and 77 g of deionized water, and mix and stir until the solution is clear. Then, under vigorous stirring, add 50 g of silica sol (SiO2 content 30 wt%) to the above solution and continue stirring for 10 min. Then add 4.47 g of 1-ethyl-2,3-dimethylimidazolium chloride template agent and continue stirring for 4 h to form a uniform, white gel. The molar composition of the gel is: 1SiO2:0.2Na2O:0.033Al2O3:23H2O:0.1SDA.

[0110] S2. Hydrothermal crystallization: The above gel was transferred to a 200 mL hydrothermal reactor with a polytetrafluoroethylene liner and subjected to static hydrothermal reaction at 170 °C for 120 h to obtain the crystallized product.

[0111] S3. Post-processing: The crystallized product is cooled, filtered, washed with deionized water until neutral, and dried at 110°C to obtain zeolite powder.

[0112] S4. Template Agent Removal and Ion Exchange: The zeolite powder was placed in a muffle furnace and calcined at 550℃ for 6 hours to remove the template agent. Then, ion exchange was performed three times at 85℃ in a 1 mol / L NH4Cl solution, each time for 6 hours. After drying, the exchanged sample was calcined again in a muffle furnace at 550℃ for 4 hours to obtain the final hierarchical porous mordenite [C2dmim]Cl-MOR (Si / Al30).

[0113] Catalytic performance evaluation: The alkylation reaction of naphthalene and propylene was evaluated according to the above analytical methods.

[0114] Characterization and performance results: The physicochemical properties and performance data of the catalyst are summarized in Tables 1 and 2.

[0115] Example 13 A method for preparing hierarchical porous mordenite using 1-butyl-3-methylpyridine-1-onium tetrafluoroborate template agent includes the following steps: S1. Preparation of aluminosilicate gel containing template agent: Weigh 4.10 g of sodium aluminate, 2 g of sodium hydroxide, and 77 g of deionized water, and mix and stir until the solution is clear. Then, under vigorous stirring, add 50 g of silica sol (30 wt% SiO2 in the silica sol) dropwise to the above solution, and continue stirring for 10 min. Then add 4.47 g of 1-butyl-3-methylpyridine-1-onium tetrafluoroborate template agent, and continue stirring for 4 h to form a uniform, white gel. The molar composition of the gel is: 1 SiO2:0.2 Na2O:0.1 Al2O3:23 H2O:0.1 SDA.

[0116] S2. Hydrothermal crystallization: The gel was transferred to a 200 mL hydrothermal reactor with a polytetrafluoroethylene liner and subjected to static hydrothermal reaction at 150 °C for 100 h to obtain the crystallized product.

[0117] S3. Post-processing: The crystallized product is cooled, filtered, washed with deionized water until neutral, and dried at 110°C to obtain zeolite powder.

[0118] S4. Template Agent Removal and Ion Exchange: The raw zeolite powder was placed in a muffle furnace and calcined at 500℃ for 8 hours to remove the template agent. Then, ion exchange was performed three times in a 1 mol / L NH4Cl solution at 95℃, each time for 4 hours. The exchanged sample was dried and then calcined again in a muffle furnace at 500℃ for 2 hours to obtain the final hierarchical porous mordenite zeolite.

[0119] Example 14 A method for preparing hierarchical porous mordenite using 1-butyl-3-methylpyridine-1-onium tetrafluoroborate template agent includes the following steps: S1. Preparation of aluminosilicate gel containing template agent: Weigh 4.10 g of sodium aluminate, 2 g of sodium hydroxide, and 77 g of deionized water, and mix and stir until the solution is clear. Then, under vigorous stirring, add 50 g of silica sol (30 wt% SiO2 in the silica sol) dropwise to the above solution, and continue stirring for 10 min. Then add 4.47 g of 1-butyl-3-methylpyridine-1-onium tetrafluoroborate template agent, and continue stirring for 4 h to form a uniform, white gel. The molar composition of the gel is: 1 SiO2:0.2 Na2O:0.1 Al2O3:23 H2O:0.1 SDA.

[0120] S2. Hydrothermal crystallization: The gel was transferred to a 200 mL hydrothermal reactor with a polytetrafluoroethylene liner and subjected to static hydrothermal reaction at 200 °C for 48 h to obtain the crystallized product.

[0121] S3. Post-processing: The crystallized product is cooled, filtered, washed with deionized water until neutral, and dried at 110°C to obtain zeolite powder.

[0122] S4. Template Agent Removal and Ion Exchange: The raw zeolite powder was placed in a muffle furnace and calcined at 600℃ for 4 hours to remove the template agent. Then, ion exchange was performed three times in a 1 mol / L NH4Cl solution at 70℃, each time for 12 hours. The exchanged sample was dried and then calcined again in a muffle furnace at 400℃ for 12 hours to obtain the final hierarchical porous mordenite zeolite.

[0123] Comparative Example 1 A method for preparing a conventional mordenite zeolite catalyst using tetraethylammonium hydroxide as a template agent, wherein the conventional mordenite zeolite catalyst is TEAOH-MOR (Si / Al10), includes the following steps: The template agent was replaced with 4g of tetraethylammonium hydroxide instead of 4.47g of 1-butyl-3-methylpyridinium-1-onium tetrafluoroborate. The remaining preparation steps and conditions were exactly the same as in Example 1, and the conventional mordenite zeolite catalyst TEAOH-MOR (Si / Al10) was finally obtained. Its physicochemical properties and catalyst performance data are summarized in Tables 1 and 2.

[0124] Comparative Example 2 A method for preparing a conventional mordenite zeolite catalyst using tetraethylammonium hydroxide as a template agent, wherein the conventional mordenite zeolite catalyst is TEAOH-MOR (Si / Al2O), includes the following steps: The template agent was replaced with 4g of tetraethylammonium hydroxide instead of 4.47g of 1-butyl-3-methylpyridine-1-onium tetrafluoroborate. The remaining preparation steps and conditions were exactly the same as in Example 2, and the conventional mordenite zeolite catalyst TEAOH-MOR (Si / Al2O) was finally obtained. Its physicochemical properties and catalyst performance data are summarized in Tables 1 and 2.

[0125] Comparative Example 3 A method for preparing a conventional mordenite zeolite catalyst using tetraethylammonium hydroxide as a template agent, wherein the conventional mordenite zeolite catalyst is TEAOH-MOR (Si / Al30), includes the following steps: The template agent was replaced with 4g of tetraethylammonium hydroxide instead of 4.47g of 1-butyl-3-methylpyridine-1-onium tetrafluoroborate. The remaining preparation steps and conditions were exactly the same as in Example 3, and the conventional mordenite zeolite catalyst TEAOH-MOR (Si / Al30) was finally obtained. Its physicochemical properties and catalyst performance data are summarized in Tables 1 and 2.

[0126] Examples 1-3 prepared [C4mpy]BF4-MOR, Examples 4-6 prepared [C4mim]Br-MOR, Examples 7-9 prepared [C4mim][OTf]-MOR, Examples 10-12 prepared [C2dmim]Cl-MOR, and Comparative Examples 1-3 prepared TEAOH-MOR. All were catalysts. The results are analyzed and discussed below: 1. Catalyst structural characterization and analysis: like Figure 1 The X-ray diffraction patterns shown are for [C4mpy]BF4-MOR, [C4mim]Br-MOR, [C4mim][OTf]-MOR, and [C2dmim]Cl-MOR prepared in Examples 1-12, and for TEAOH-MOR prepared in Comparative Examples 1-3. All patterns are consistent with the characteristic diffraction peaks of the mordenite standard card, and the peaks are sharp without significant broadening. This indicates that the synthesized series of samples all have good crystallinity, and also proves that the introduction of the template agent did not destroy the basic framework structure of the zeolite.

[0127] Figure 2 The nitrogen adsorption-desorption isotherms of various hierarchical porous mordenite zeolites are presented. The results show that the samples from Examples 1 to 12 all exhibit a composite isotherm of type I and type IV, and a significant H4-type hysteresis loop appears in the relative pressure range of 0.4–0.9, which strongly demonstrates the successful introduction of the mesoporous structure. As shown in Table 1, the catalysts synthesized via the template agent method in the examples all possess superior external specific surface area and considerable mesoporous pore volume.

[0128] like Figure 3 As shown in the figure, the SEM morphology of hierarchical porous mordenite zeolite under different combinations of ionic liquid templates and Si / Al ratios is presented. In terms of templates, when [C4mim][OTf] is used as a template, the samples in column 3 exhibit a unique layered / plate-like stacked structure, especially with Si / Al=10 and 20, where the morphology is more regular. Samples with [C4mpy][BF4], [C4mim]Br, and [C2dmim]Cl as templates mostly show granular or agglomerated morphologies, reflecting the regulatory effect of the anion / cation type of the ionic liquid on the morphology of hierarchical porous mordenite zeolite. In terms of Si / Al ratio, as the Si / Al ratio increases from 10 to 30, the grain size of most samples tends to decrease. For example, under the [C4mpy][BF4] template, the particles are significantly refined when Si / Al=30, which is related to the effect of the Si / Al ratio on the growth rate of hierarchical porous mordenite zeolite.

[0129] It is noteworthy that the hierarchical porous mordenite zeolites of Examples 1-12 prepared using ionic liquids as templates exhibit significantly higher external surface area ratios and mesopore volumes compared to Comparative Examples 1-3, which used monoquaternary ammonium salt TEAOH as templates. This demonstrates the unique advantages of ionic liquid templates in constructing zeolite structures with specific pore sizes and morphologies. The mechanism of action lies in the designability of both cations and anions in ionic liquids. The cation portion can specifically interact with active sites in the zeolite framework precursor by adjusting the alkyl chain length and heterocyclic structure. The anion portion can regulate the polymerization rate of the precursor through hydrogen bonding and electrostatic interactions. Furthermore, the steric hindrance effect of the ionic liquid molecules as a whole acts as both "template guidance" and "spatial confinement," guiding the directional alignment of framework atoms during zeolite crystallization, thereby forming zeolite channels with uniform pore size and regular structure. With the increase of cation heterocyclic substituents in ionic liquids or the improvement of alkyl chain branching, the microporous order and the exposure ratio of specific crystal faces of zeolites are improved, indicating that tunable ionic liquids are beneficial for the synthesis of high-performance zeolites with targeted structures.

[0130] Table 1. Physicochemical Properties of Catalysts 2. Characterization and analysis of catalyst acidity: In the long-term research process of alkylation reactions, the acidity of the catalyst has always been recognized as a core factor directly affecting the selectivity of the reaction. This rule has been universally verified in various types of alkylation reactions, such as alkane alkylation and aromatic alkylation. Regarding the core acidity properties of the catalyst in the system of this invention, such as the range distribution of acid strength, the proportion of different types of acid sites, and key information on the availability of acid sites, all have been... Figure 4 , Figure 5 The visualization results and the detailed parameter list in Table 2 are presented in a thorough and detailed manner. These characterization data not only clearly present the acidic characteristics of the current catalyst, but also provide valuable reference for the subsequent performance optimization and structural design of catalysts in this field.

[0131] Ammonia temperature-programmed desorption, a classic characterization technique for the qualitative and quantitative analysis of acidic sites in catalysts, is widely used in academia due to its high reliability and strong specificity. The test results obtained using this technique in this invention are... Figure 4The corresponding ammonia desorption spectra obtained from the temperature-programmed desorption process and the quantitative data related to the desorption peaks in Table 2 clearly show that all prepared catalyst samples exhibit two highly distinctive ammonia desorption peaks. Further analysis reveals that the low-temperature desorption peak at approximately 220°C originates from weak and moderately strong acid sites on the catalyst surface. These acidic sites, due to their moderate acidity, often serve as active centers participating in mild surface adsorption processes and low-energy-barrier catalytic reaction steps within the reaction system. Conversely, the high-temperature desorption peak at approximately 430°C corresponds to strong acid sites on the catalyst surface. The acidity and quantity distribution of these strong acid sites directly regulate the formation pathway of intermediates during the catalytic reaction and have a crucial impact on the overall reaction efficiency and the formation rate of the target product.

[0132] To clarify the acidity advantage of the hierarchical porous mordenite zeolite of this invention, a systematic comparative test was conducted with a conventional mordenite zeolite catalyst synthesized using tetraethylammonium hydroxide, a traditional template agent. The test results show that although the total acidity of the hierarchical porous mordenite zeolite prepared in each embodiment of this invention is slightly lower than that of the conventional TEAOH-MOR catalyst, the core difference lies in the precise controllability of the strength of the strong acid centers. Specifically, the high-temperature desorption peak of the conventional TEAOH-MOR catalyst reaches 455℃, indicating the presence of numerous extremely strong acidic sites on its surface. In contrast, the high-temperature desorption peak of the hierarchical porous mordenite zeolite samples from Examples 1 to 12 of this invention significantly shifts to the low-temperature range and remains stable within the range of 420℃ to 430℃. This characteristic peak shift directly confirms that the strength of the strongest acid center has been effectively weakened and precisely controlled.

[0133] Catalytic reaction mechanism analysis reveals that excessively strong acidic sites on the catalyst surface are key factors inducing deep alkylation, olefin polymerization, and carbon deposition side reactions. These side reactions not only deplete reactants and reduce the yield of the target product but also lead to the covering or blockage of catalyst active sites, ultimately accelerating catalyst deactivation. Therefore, this invention achieves a moderate weakening of the strong acid strength of the catalyst through a modulated template agent synthesis strategy. This retains the acidic activity required for catalytic alkylation while suppressing side reactions initiated by excessively strong acidity. The design of this invention has significant practical application value and theoretical guiding significance for significantly improving target product selectivity, extending catalyst lifespan, and improving cycle stability.

[0134] Table 2. Properties of the acidic sites of the catalyst 3. Catalytic performance evaluation: The alkylation reaction of naphthalene and propylene to synthesize diisopropylnaphthalene was used as the research object. Figure 6The continuous fixed-bed reactor shown was used to test the catalyst performance. A catalyst with a particle size of 60-80 mesh was selected, and 2.5 g of catalyst was uniformly packed into the isothermal section of the fixed-bed reactor with an inner diameter of 10 mm for catalytic experiments. A naphthalene solution was fed into the preheating section at a flow rate of 0.15 mL / min using a metering pump, while propylene was simultaneously introduced through a mass flow controller, adjusting the molar ratio of naphthalene to propylene to 1:3.

[0135] Reaction conditions were controlled as follows: the temperature of the reactor isothermal zone was set at 240℃~280℃, the system pressure was maintained at 1.5MPa~2.0MPa, and the mass hourly space velocity (MHV) was controlled at 2.0 h⁻¹. -1 After 30 minutes of stable feeding, the reaction system enters the steady-state stage.

[0136] During the continuous reaction, samples were taken at the outlet at regular intervals, and the products were detected and analyzed using a ThermoFisher Trace 1300 gas chromatograph equipped with an SE-30 capillary column; the SE-30 capillary column has dimensions of 30m × 0.32mm × 0.25μm.

[0137] The evaluation results of the catalytic performance are shown in Table 3, which ultimately verified the superiority of the technical solution of the present invention.

[0138] Table 3. Catalyst Performance Evaluation Table The performance differences between different catalysts are clearly observed from the catalytic performance evaluation data listed in Table 3: the comparative example, TEAOH-MOR, exhibits poor catalytic performance, with low selectivity for 2,6-diisopropylnaphthalene, low yield of the target product, and low catalyst cycle life. This result is perfectly consistent with the structural characteristics and acidity distribution of this catalyst—the purely microporous crystal structure hinders the diffusion of macromolecular reactants and products within the pores, resulting in severe mass transfer limitations. Simultaneously, the unsuitable distribution of acidic sites further exacerbates side reactions, ultimately leading to deterioration of catalytic performance.

[0139] The hierarchical porous mordenite zeolites prepared in Examples 1 to 12 of this invention all exhibited excellent catalytic performance. Among them, the [C4mim][OTf]-MOR(Si / Al2O) of Example 8 showed the most outstanding performance: its 2,6-diisopropylnaphthalene selectivity reached 44.1%, the 2,6- / 2,7-diisopropylnaphthalene molar ratio reached 4.44, and the [C4mim][OTf]-MOR(Si / Al2O) had a continuous operating life of up to 228 hours, with all indicators far exceeding those of traditional catalysts. This excellent result fully demonstrates that the hierarchical porous mordenite zeolite prepared by the synthesis method established in this invention, with the help of precise control of ionic liquids, forms a synergistic and complementary structure and acidity advantage—the optimal mesoporous network constructed by the template agent effectively eliminates mass transfer limitations, ensuring that reactants quickly reach the active sites and desorb products in a timely manner; while the moderate strong acid strength and high B / L ratio inhibit deep alkylation and isomerization side reactions, and the B / L ratio is a Brønsted acid / Lewis acid ratio, which strengthens the formation pathway of the target product. The synergistic effect of the two fundamentally solves the core bottleneck problems of low catalyst mass transfer efficiency and easy deactivation in existing technologies.

[0140] In summary, this invention, by introducing an ionic liquid template agent, successfully overcomes the technical limitations of conventional mordenite catalyst synthesis, preparing a novel mordenite catalyst that combines a hierarchical pore structure with optimized acidity distribution. This catalyst fundamentally solves the two key challenges faced by conventional mordenite catalysts in the alkylation of large aromatic hydrocarbons: hindered mass transfer and rapid deactivation. In the synthesis of 2,6-diisopropylnaphthalene, it achieves an unprecedented balance of high selectivity, high yield, and high stability. This not only represents significant technological progress and fills a performance gap in this field, but also possesses the potential for large-scale industrial application, providing a new technical solution and development direction for the efficient and green synthesis of related fine chemical products.

[0141] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-level porous mordenite zeolite, characterized in that, Multi-level porous mordenite is a type of zeolite made from... , , , One of the methods involves using a template agent. This is achieved by hydrothermally crystallizing an aluminosilicate gel containing the template agent, followed by removing the template agent, to obtain sodium-type hierarchical porous silicate zeolite. The sodium-type hierarchical porous silicate zeolite is then subjected to NH4+ treatment. 4+ Replace Na + Subsequently, sintering is performed to form active Si-OH-Al-linked hydroxyl groups, resulting in hierarchical porous mordenite.

2. The multi-level porous silica zeolite according to claim 1, characterized in that, The total specific surface area of ​​hierarchical porous mordenite is 350 m². 2 / g~450m 2 / g.

3. The multi-level porous silica zeolite according to claim 1, characterized in that, The total pore volume of the hierarchical porous mordenite is 0.25 cm³. 3 / g~0.35cm 3 / g, of which the mesoporous pore volume is 0.05cm³. 3 / g~0.1cm 3 / g.

4. The multi-level porous silica zeolite according to claim 1, characterized in that, In hierarchical porous mordenite, the molar ratio of the integral area of ​​Brønsted acid sites to Lewis acid sites is 5~10:

1.

5. A method for preparing the multi-level porous mordenite zeolite according to claim 1, characterized in that, Includes the following steps: After mixing silicon source, aluminum source, alkali source and water, an ionic liquid is added as a template agent and mixed evenly to obtain aluminosilicate gel containing the template agent. Among them, ionic liquids are selected from , , , One of them; The aluminosilicate gel containing the template agent was subjected to hydrothermal crystallization, and then filtered, washed until neutral, and dried to obtain zeolite raw powder. The raw zeolite powder was calcined to remove the template agent, resulting in sodium-type hierarchical porous mordenite. Sodium-type hierarchical porous mordenite was mixed with an ammonium salt solution, then subjected to ion exchange, and finally sintered to obtain hierarchical porous mordenite.

6. The method for preparing multi-level porous mordenite according to claim 5, characterized in that, In the aluminosilicate gel containing the template agent, the molar ratio of each component is SiO2:Al2O3 = 15~50:1; template agent:SiO2 = 0.05~0.2:1; H2O:SiO2 = 20~50:

1.

7. The method for preparing multi-level porous mordenite according to claim 5, characterized in that, The conditions for hydrothermal crystallization are: hydrothermal crystallization at 150℃~200℃ for 48h~120h.

8. The method for preparing multi-level porous mordenite according to claim 5, characterized in that, The ion exchange method is as follows: Sodium-type hierarchical porous mordenite is placed in an ammonium salt solution and stirred at 70℃~95℃ for 4h~12h, and repeated at least 3 times.

9. The method for preparing multi-level porous mordenite according to claim 5, characterized in that, The sintering conditions are: calcination at 400℃~550℃ for 2h~12h.

10. The application of the hierarchical porous mordenite of claim 1 as a catalyst for naphthalene alkylation reaction, characterized in that, The application method is as follows: Using naphthalene and propylene as raw materials, and hierarchical mordenite as catalyst, the reaction was carried out at a temperature of 200℃~325℃, a reaction pressure of 1.0MPa~5.0MPa, a molar ratio of naphthalene to propylene of 1:2~6, and a mass hourly space velocity of 1h⁻¹. −1 ~5h −1 Under these conditions, naphthalene alkylation reaction is carried out; Here, mass hourly space velocity (MHSV) is the flow rate ratio of the total mass of naphthalene and propylene to the mass of the catalyst with hierarchical porous mordenite.

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